How can an Android photosphere be used as a scene background?
Yes, there's a easy way;
Cycles
Just go to the Node Editor, change the type to World.

Then, check Use Nodes, if it isn't already, press Shift + A and add a Texture&gt;Environment Texture node; Point the to your file, and connect it to the Background node.
If you don't like/understand the Node Editor, you can go to the Properties, switch to the World tab, and click Use Nodes, then besides the Color field, click the dot, and select Texture&gt;Environment Texture and point it to your image.

Blender Internal
Go to the Properties panel, switch to the World tab, go to the World subsection, and check Blend Sky and Real Sky.

Then go to the Texture tab, click New click World under Preview and open your image. Scroll down to the Influence subsection and check 'Zenith Up', Zenith Down, Horizon and Blend.
Then go to the Mapping, and change the Coordinate field from View to Equirectangular.